Oral compositions which inhibit calculus formation on dental surfaces are highly desirable since calculus is one of the causative factors in periodontal conditions. The reduction of calculus, therefore, promotes oral hygiene. Polyphosphates, such as tetraalkali metal pyrophosphates, are examples of anticalculus agents.
Dental plaque is a precursor of calculus. Unlike calculus, however, plaque may form on any part of the tooth surface, particularly at the gingival margin. Hence, besides being unsightly, it is implicated in the occurrence of gingivitis.
Accordingly, it is desirable to include effective antiplaque agents in oral compositions, optionally in combination with an anticalculus agent. Antiplaque agents found particularly effective are noncationic antibacterial agents, such as halogenated diphenyl ethers, especially Triclosan (2',4',4'-2-trichloro-2-hydroxydiphenyl ether), as disclosed in Gaffar et al., U.S. Pat. No. 5,037,637, incorporated herein by reference. However, since halogenated diphenyl ethers and other noncationic antibacterial agents are not readily soluble in water, alternate solvents are desirable to optimize their effectiveness.
Pyrrolidone compounds, other than N-methylpyrrolidone, have previously been employed for a variety of purposes in oral compositions. For example, Roberts et al., Reissue U.S. Pat. No. 29,634 discloses the use of polyvinyl pyrrolidone (PVP) as a binder to form a polishing agent into agglomerated particles. PVP is disclosed as a viscosity adjuster in Prussin, U.S. Pat. No. 3,954,962, as a gelling agent in Norfleet, U.S. Pat. No. 3,840,657, a cooling agent in Humbert et al., U.S. Pat. No. 3,917,613, and a synthetic gum in Aguilar U.S. Pat. No. 4,344,931. PVP is further disclosed for uses in other oral compositions with hydrogen peroxide. Both Simon et al, U.S. Patent Nos. 4,521,403 and 4,567,036 teach to the use of PVP with hydrogen peroxide in controlling disease of the teeth and periodontum. Merianos et al, U.S. Pat. No. 5,130,124 teaches to the use of PVP as a film forming antimicrobial composition when combined with hydrogen peroxide.
Pyrrolidone compounds have also been incorporated into dentifrice compositions to kill bacteria and/or retard the formation of plaque and tartar. Ploger et al., U.S. Pat. No. 3,960,888, disclose pyrrolidone-5,5-diphosphonic acids as antitartar and antiplaque agents. Murdrak, U.S. Pat. No. 2,757,125, discloses N-higher alkyl-4-carboxy-2-pyrrolidones as antibacterial agents for oral compositions. Login et al., U.S. Patent Nos. 4,732,990; 4,830,850; and 4,837,013 disclose quaternized nitrogen compounds including derivatives of pyrrolidone as antibacterial agents for dentifrice compositions and/or mouthwashes.
Substituted pyrrolidone compounds have been used to retard plaque formation as disclosed in Blackburne et al, U.S. Pat. No. 4,093,711; Shapiro et al., U.S. Pat. Nos. 4,117,107 and 4,117,108: and Hollister, U.S. Pat. No. 4,621,120.
Dunn et al. U.S. Pat. No. 4,975,271, teaches to use N-methylpyrrolidone as one of several skin penetration enhancer solvents for a drug or bioactive agent which is applied directly to oral mucosa. Dental surfaces are not contacted. Mouthrinses and other topically applied oral medicinal agents which would contact dental surfaces as well as oral mucosa are specifically excluded.
It would be desirable to enhance the solubility of noncationic antibacterial agents to improve their effectiveness. It would also be desirable to provide an oral composition containing an antiplaque agent with enhanced antiplaque effectiveness.